任何语编程都有对应的调试工具，如java有Debug、mysql有调试工具、js有调试工具等，shell也不例外
shell的语法检测：相当于java的编译
1. shell语法检测：
sh -n ./test.sh (sh是/bin/sh 是系统提供的可执行脚本)
2. shell的普通调试：
sh -x ./test.sh
如test.sh的内容如下：
#!/bin/bash
echo "welcome to shell debug"
for i in 1 2 3 4 5 6
do
echo $i
done
echo "shell debug is over"
执行sh -x ./test.sh该语句后如下：
- echo ‘welcome to shell debug’
welcome to shell debug- for i in 1 2 3 4 5 6
- echo 1
1- for i in 1 2 3 4 5 6
- echo 2
2- for i in 1 2 3 4 5 6
- echo 3
3- for i in 1 2 3 4 5 6
- echo 4
4- for i in 1 2 3 4 5 6
- echo 5
5- for i in 1 2 3 4 5 6
- echo 6
6- echo ‘shell debug is over’
shell debug is over
3. shell的中断调试
在shell中添加一个睡眠，保证可以有时间中断调试 sleep 3 睡眠3秒执行下一个语句
#!/bin/bash
echo "welcome to shell debug"
for i in 1 2 3 4 5 6
do
echo $i
sleep 3
done
echo "shell debug is over"
在调试过程中可以按Ctrl + Z中断调试，观察结果，然后再按fg键继续调试即可。(先按f在按g键)
4. 使用调试工具-bashdb
【功能】: 类似于GDB的调试工具，可以完成对shell脚本的断点设置，单步执行，变量观察等许多功能
【场合】: 脚本比较大时，通过-x参数调试时已不方便时.
【用法】:
bashdb -c script.sh
bashdb script.sh
bashdb --debugger script.sh
【说明】:该工具默认未安装，当前最新版本为:4.4-0.92,下载目录:http://bashdb.sourceforge.NET/
1). 如果是ubuntu系统,直接用apt-get来安装
apt-get install bashdb
2). 如果是Centos等版本，使用windows下载后，编译，安装，大致步骤如下:
下载：https://sourceforge.net/projects/bashdb/files/bashdb/
[root@hadoop007 ~]# tar -xzvf bashdb-4.4-0.92.tar.gz -C /usr/src
[root@hadoop007 ~]# cd /usr/src/bashdb-4.4-0.92
[root@hadoop007 ~]# ./configure
[root@hadoop007 ~]# make install
【示例】:
vi /home/test1.sh
#!/bin/bash
echo "----------------begin-----------------"
MAX=3
for ((i = 0; i < MAX; i++))
do
nowdate=`date -d"-$i day" +%Y-%m-%d`
echo $nowdate
done
echo "----------------end-----------------"
调试命令：
./bashdb --debugger /home/test.sh
[root@hadoop007 bashdb-4.4-0.92]# ./bashdb --debugger /home/test.sh
bash debugger, bashdb, release 4.4-0.92
Copyright 2002, 2003, 2004, 2006-2012, 2014 Rocky Bernstein
This is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
(/home/test.sh:3):
3: echo "----------------begin-----------------"
bashdb<0> n #执行下一条语句
----------------begin-----------------
(/home/test.sh:4):
4: MAX=3
bashdb<1> l #列出当前行上下各5行，总共10行
1: #!/bin/bash
2:
3: echo "----------------begin-----------------"
4: => MAX=3
5: for ((i = 0; i < MAX; i++))
6: do
7: nowdate=`date -d"-$i day" +%Y-%m-%d`
8: echo $nowdate
9: done
10: echo "----------------end-----------------"
bashdb<2> b 7 #在行号为7的行设置断点
Breakpoint 1 set in file /home/test.sh, line 7.
bashdb<3> c #继续运行
Breakpoint 1 hit (1 times).
(/home/test.sh:7):
7: nowdate=`date -d"-$i day" +%Y-%m-%d`
bashdb<4> print $i
0
bashdb<5> n
(/home/test.sh:8):
8: echo $nowdate
bashdb<6> print $nowdate
2017-03-20
bashdb<7> c 10 #单步往下运行10步
One-time breakpoint 2 set in file /home/test.sh, line 10.
2017-03-20
Breakpoint 1 hit (2 times).
(/home/test.sh:7):
7: nowdate=`date -d"-$i day" +%Y-%m-%d`
bashdb<8> finish #运行到结束
Breakpoint 1 hit (3 times).
(/home/test.sh:7):
7: nowdate=`date -d"-$i day" +%Y-%m-%d`
date -d"-$i day" +%Y-%m-%d
bashdb<(9)> finish
2017-03-19
Breakpoint 1 hit (4 times).
(/home/test.sh:7):
7: nowdate=`date -d"-$i day" +%Y-%m-%d`
bashdb<10> finish
Breakpoint 1 hit (5 times).
(/home/test.sh:7):
7: nowdate=`date -d"-$i day" +%Y-%m-%d`
date -d"-$i day" +%Y-%m-%d
bashdb<(11)> finish
2017-03-18
(/home/test.sh:10):
10: echo "----------------end-----------------"
bashdb<12> q #退出
bashdb: That's all, folks...
